Question

The overall ΔGº' of glycolysis is -79.9 kJ/mol, while the overall ΔGº' for gluconeogenesis is -42.7 kJ/mol.

What would be the ΔGº' of the synthesis of glucose from pyruvate if the pathway was the reverse reactions of glycolysis? Answer in kJ/mol

There are four enzymes that are unique to gluconeogenesis. List them in order from occurrence in the direction of pyruvate to glucose synthesis. Spelling counts, case insensitive.

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Although glycolysis and gluconeogenesis are reverse pathways, they are both exergonic pathways. The synthesis of glucose from pyruvate, although exergonic, is energetically expensive.

If glycolysis were able to run in the reverse direction (using the same reactions), how many net ATP would be input?

How many high-energy phosphate groups (as either ATP or GTP) are required for the synthesis of glucose from pyruvate by gluconeogenesis?

Answer 1

1. If the path was the reverse reactions the energy would be +79.9kJ/mol

2

Pyruvate Carboxylase (PC)

PEP carboxykinase (PEPCK)

fructose bisphosphatase (FBPase)

glucose-6-phosphatase (G6Pase)

3. You would net 1 ATP per mol of pyruvate, since you need two pyruvates for 1 mole of glucose the net investment would be 2 ATP.

4 You need 2 ATP and 1 GTP per mole of pyruvate, since you need two moles of pyruvate to produce 1 mole of glucoso the net required is 4ATP and 2 GTP--->6 high-energy phosphate groups.